On the thermal structure and stability of configurations with heat diffusion and a gain-loss function. I - General results

1992 ◽  
Vol 398 ◽  
pp. 177 ◽  
Author(s):  
Ibanez S. Miguel H. ◽  
Antonio Parravano ◽  
Mendoza B. Cesar A.
Keyword(s):  
Loss Function ◽  
Thermal Structure ◽  
Heat Diffusion ◽  
Structure And Stability ◽  
Gain Loss

Measurement of the thermal conductivity of thin layers using a scanning thermal microscope

2001 ◽  
Vol 16 (9) ◽  
pp. 2530-2543 ◽  
Author(s):  
Erwin R. Meinders
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Structure ◽  
Thin Layers ◽  
Heat Diffusion ◽  
Sputter Deposited ◽  
Relative Differences ◽  
Conductivity Of Thin Films ◽  
Change Material

A scanning thermal microscope (SThM) was used to measure the thermal conductivity of thin sputter-deposited films in the thickness range of 10 nm–10 μm. The SThM method is based on a heated tip that is scanned across the surface of a sample. The heat flowing into the sample is correlated to the local thermal conductivity of the sample. Issues like the contact force, the surface roughness of the sample, and tip degradation, which determine to a great extent the contact area between tip and surface, and thus the heat flow to the sample, are addressed in the paper. A calibration curve was measured from known reference materials to quantify the sample heat flow. This calibration was used to determine the effective thermal conductivity of samples. Further, the heat diffusion through a layered sample due to a surface heat source was analyzed with an analytical and numerical model. Measurements were performed with films of aluminum, ZnS–SiO2, and GeSbTe phase change material of variable thickness and sputter-deposited on substrates of glass, silicon, or polycarbonate. It is shown in the paper that the SThM is a suitable tool to visualize relative differences in thermal structure of nanometer resolution. Determination of the thermal conductivity of thin layers is possible for layers in the micrometer range. It is concluded that the SThM is not sensitive enough to measure accurately the thermal conductivity of thin films in the nanometer range. Suggestions for improvement of the SThM method are given.

scholarly journals Critical Quality Source Diagnosis for Dam Concrete Construction Based on Quality Gain - loss Function

2014 ◽  
Vol 7 (2) ◽  
pp. 137-151 ◽  
Author(s):  
Bo Wang ◽  
◽  
Zhiyong Li ◽  
Junyan Gao ◽  
Heap Vaso ◽  
...  
Keyword(s):  
Loss Function ◽  
Concrete Construction ◽  
Dam Concrete ◽  
Gain Loss ◽  
Source Diagnosis

Quality Gain-Loss Function and Its Empirical Analysis in Dam Concrete Construction

2020 ◽  
Vol 104 (sp1) ◽  
Author(s):  
Bo Wang ◽  
Hougui Zhou ◽  
Zhiyong Li ◽  
Tianyu Fan ◽  
Xiangtian Nie
Keyword(s):  
Empirical Analysis ◽  
Loss Function ◽  
Concrete Construction ◽  
Dam Concrete ◽  
Gain Loss

Heat thermal structure in the interfacial boundary layer measured in an open tank of water in turbulent free convection

1977 ◽  
Vol 83 (2) ◽  
pp. 311-335 ◽  
Author(s):  
Kristina B. Katsaros ◽  
W. Timothy Liu ◽  
Joost A. Businger ◽  
James E. Tillman
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Standard Deviation ◽  
Theoretical Calculations ◽  
Thermal Structure ◽  
The Body ◽  
Heat Diffusion ◽  
Return Flow ◽  
Experimental Conditions ◽  
Heat Diffusion Equation

The thermal structure in the boundary layer and its relation to the heat flux from the cooling and evaporating surface of a deep tank of water are investigated. When a deep layer of water in contact with still air above loses heat to the air, the cooled water in a region just under the surface converges along lines and then plunges down in sheets. These sheets of falling water dissipate as they move into the body of the water, which is in turbulent motion. The vertical profiles of the horizontally averaged temperature and its standard deviation agree fairly closely with theoretical profiles based on time averages of the solution to the heat diffusion equation. The differences between observed and thus predicted profile shapes are consistent with the expected effects of the falling cold thermals and the warm return flow, which are neglected in the theories. The profiles of the standard deviation have large values up to the interface and lie between predictions based on boundary conditions of constant surface temperature and constant heat flux, in keeping with the experimental conditions.The relation between the net heat flux and the temperature difference across the boundary layer is given in non-dimensional form by N = 0[sdot ]156R0[sdot ]33, which is in good agreement with the asymptotic similarity prediction N [vprop ] R1/3 but lower than theoretical calculations of the upper bound of N vs. R.

scholarly journals Optimization Model of Engineering Specifications Based on Grey Quality Gain-Loss Function

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1327
Author(s):  
Bo Wang ◽  
Qi Yang ◽  
Chen Liu ◽  
Qikai Li ◽  
Xiangtian Nie
Keyword(s):  
Quality Control ◽  
Loss Function ◽  
Optimization Model ◽  
Quality Characteristics ◽  
Function Model ◽  
Construction Quality ◽  
Concrete Construction ◽  
Target Values ◽  
Dam Concrete ◽  
Gain Loss

In view of the fact that the target values of some quality characteristics are grey, the grey quality gain-loss function model was applied in the analysis of the quality characteristics. At the same time, based on the analysis of engineering specifications and process capability, an optimization model of engineering specifications was proposed to minimize the expected total loss of each product and maximize the expected compensation with inspection costs, scrap costs and grey quality gain-loss into consideration. The optimal engineering specification can be obtained by using the optimization model. Through the example analysis and its application in dam concrete construction, the practicability of the model is verified, which provides an important reference for the research of the new theory of dam concrete construction quality control.

scholarly journals $${\mathcal {PT}}$$ PT -symmetric dimers with time-periodic gain/loss function

2014 ◽  
Vol 117 (2) ◽  
pp. 663-672 ◽  
Author(s):  
Demetra Psiachos ◽  
Nikos Lazarides ◽  
G. P. Tsironis
Keyword(s):  
Loss Function ◽  
Gain Loss ◽  
Time Periodic
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